I get "transfer of 'example.net/IN' from 192.168.4.12#53: failed while receiving responses: permission denied" error messages.
A:

These indicate a filesystem permission error preventing named creating / renaming the temporary file. These will usually also have other associated error messages like

"dumping master file: sl/tmp-XXXX5il3sQ: open: permission denied"

Named needs write permission on the directory containing the file. Named writes the new cache file to a temporary file then renames it to the name specified in named.conf to ensure that the contents are always complete. This is to prevent named loading a partial zone in the event of power failure or similar interrupting the write of the master file.

Note file names are relative to the directory specified in options and any chroot directory ([<chroot dir>/][<options dir>]).

If named is invoked as "named -t /chroot/DNS" with the following named.conf then "/chroot/DNS/var/named/sl" needs to be writable by the user named is running as.